Assuming you mean the cables running to the box right near the end of the exhaust, I think it more likely to be an exhaust gas sensor (O2?). An EXUP style valve wouldn't be so near the end of the exhaust adn, for that matter, would not be likely used in racing.

Most, if not all, of the bikes in this class will be using a seperate 02 sensor for each cylinder and they usually only have a single lead coming from them.

The Aprilia RSV4 World Superbike machines have something very similar looking attached to their exhaust system, as do the ART bikes. Right where you'd expect to see a EXUP type butterfly valve, with two actuator cables coming out, just like my old K6 GSX-R.

The Aprilia exhaust has all the headers joining up and exiting through a single outlet but the arrangement the Ducati uses, with each side of the vee having its own 2-1 pipe, you'd need a seperate butterfly valve for each bank of cylinders. Ideally situated near to the point where the two pipes have joined up. It's hard to tell exactly from the above image, due to the angle it was taken from, but it looks to me like that's right where it is.

Perhaps the site proprietor can request that Mr Gosling get in nice and close for a more detailed shot? ;)